require('script-loader!file-saver');
import * as XLSX from 'xlsx'
import * as XLSXStyle from 'xlsx-style'
function s2ab(s) {
    const buf = new ArrayBuffer(s.length);
    const view = new Uint8Array(buf);
    for (let i = 0; i < s.length; i++) {
        view[i] = s.charCodeAt(i) & 0xFF;
    }
    return buf;
}
// 根据dom导出表格
export function exportToExcel(idSelector, fileName, titleNum = 1) {
    // 设置导出的内容是否只做解析，不进行格式转换     false：要解析， true:不解析
    const xlsxParam = { raw: true }
    let table = document.querySelector(idSelector).cloneNode(true);
 
    // 因为element-ui的表格的fixed属性导致多出一个table，会下载重复内容，这里删除掉
    if (table.querySelector('.el-table__fixed-right'))
        table.removeChild(table.querySelector('.el-table__fixed-right'));
    if (table.querySelector('.el-table__fixed'))
        table.removeChild(table.querySelector('.el-table__fixed'));
 
    const wb = XLSX.utils.table_to_book(table, xlsxParam)
    let range = XLSX.utils.decode_range(wb.Sheets['Sheet1']['!ref']);
    let cWidth = [];
    for (let C = range.s.c; C < range.e.c; ++C) {   //SHEET列
        let len = 100; //默认列宽
        let len_max = 400; //最大列宽
        for (let R = range.s.r; R <= range.e.r; ++R) {  //SHEET行
            let cell = { c: C, r: R };                    //二维 列行确定一个单元格
            let cell_ref = XLSX.utils.encode_cell(cell);  //单元格 A1、A2
            if (wb.Sheets['Sheet1'][cell_ref]) {
                // if (R == 0){
                if (R < titleNum) {
                    wb.Sheets['Sheet1'][cell_ref].s = {  //设置第一行单元格的样式 style
                        alignment: {
                            horizontal: 'center',
                            vertical: 'center',
                        },
                    };
                } else {
                    wb.Sheets['Sheet1'][cell_ref].s = {
                        alignment: {
                            horizontal: 'center',
                            vertical: 'center',
                        },
                    };
                }
                //动态自适应：计算列宽
                let va = JSON.parse(JSON.stringify(wb.Sheets['Sheet1'][cell_ref].v));
                var card1 = JSON.parse(JSON.stringify(va)).match(/[\u4e00-\u9fa5]/g); //匹配中文
                var card11 = "";
                if (card1) {
                    card11 = card1.join("")
                }
                var card2 = JSON.parse(JSON.stringify(va)).replace(/([^\u0000-\u00FF])/g, "");  //剔除中文
                let st = 0;
                if (card11) {
                    // st += card11.length * 16  //中文字节码长度
                    st += card11.length * 20  //中文字节码长度
                }
                if (card2) {
                    // st += card2.length * 8  //非中文字节码长度
                    st += card2.length * 10  //非中文字节码长度
                }
                if (st > len) {
                    len = st;
                }
            }
        }
        if (len > len_max) {//最大宽度
            len = len_max;
        }
 
        cWidth.push({ 'wpx': len });     //列宽
    }
    wb.Sheets['Sheet1']['!cols'] = cWidth
    const wbout = XLSXStyle.write(wb, { bookType: 'xlsx', bookSST: false, type: 'binary' })
    try {
        saveAs(new Blob([s2ab(wbout)], { type: '' }), `${fileName}.xlsx`)
    } catch (e) {
        if (typeof console !== 'undefined') {
            console.log(e, wbout)
        }
    }
    return wbout
}